As many of the others have said above, this is a situation where each and every person has a different experience, reason and situation. I'll share my observations and experiences.
My entire professional life has been outside India. I lived in Kuwait from 2013 to 2022, and moved to Sydney, Australia to do my MBA and working here since. Had three reasons to do it.
1. The Kuwait market had slowed down drastically from 2015 and as a result growth had become nonexistent.
2. Got married in Dec 2021, my wife (Also an NRI) had lived in Bangkok and couldn't live in a place as restricted as Kuwait.
3. Australia had a relatively easy entry path. (It's still not difficult, just not as easy)
Living in Kuwait, I used to travel to Chennai 6-7 times a year. A journey from doorstep to doorstep took about 8 hours. It's short enough that I have done weekend trips a few times and on average most trips were 6-7 days. This helped me see and spend time with family and friends a lot and I never felt away.
Now, I could never do that as the shortest journey from doorstep to doorstep is around 17 hours and costs thrice as much. So, flying home happens once a year. I stay for a month but every trip I can see a difference in the parents. Age is catching up and it's an uneasy feeling. Even friends lives are changing so much that I have to adjust my expectations of the trip. By the time I have relaxed, I'm flying back.
Luckily, in terms of friends, both places have been very good for me. I am a social person and make plans which helps build that friends circle quite easily. Organised quite a few TBhp meets in Sydney to build that car circle.

I did a bit of schooling in Kuwait so when I went there after college, I had friends who were also moving around the same time. In Sydney, since I moved to do my MBA, again friends have been easy to make. So, there is no question of boredom or loneliness. We have things to do almost every other day and as a result time flies. But for many of the others, that doesn't come easy. There was a report that Sydney is the second hardest place on Earth to make friends and I don't doubt it. Moving here with a PR means unless there is someone already here who is somewhat close things are going to be quiet. To give an example, my wife has distant cousins here. We meet them once in six months. Tons of laughs and a properly good time but they have childhood friends they have grown up with here in Sydney and they meet up more often the way we meet up with our friends more often.
In terms of career, my wife and I have had the polar opposite in terms of jobs. She has had a significantly easier time than I have. I got a student visa and she was my dependent. That gave her full working rights. With prior experience in a MNC, she got offers before we even moved. I was doing a career change and Australia is probably the worst country to do that in. Hence, I am basically restarting my career from scratch but I am able to leverage the previous experience and am confident growth is not far away.
Pretty much all my immigrant MBA classmates who moved here with plans to change career or industry did not do that. They took similar roles to their previous ones.
Healthwise, things are different for sure, some good and some bad.
Environment is cleaner and the weather is significanly more comfortable year round. Even Europeans are immigrating to Australia citing weather.
Food is unhealthy on the other hand. Selling with a tag "No added hormones" doesn't mean the decades of adding hormones and other chemicals can be undone (Australian KFC chicken wings are the same size as Indian KFC chicken legs). I am eating more bland and boring food than ever before yet I am fatter and cholesterol is higher.
Medical services are slow, unless it's an emergency, people have to wait. Hairline fractures, extended period of sickness, horrible toothache, etc doesn't matter. Wait a few months before your turn. India and Kuwait on the other hand, immediate access to a doctor.
Quality of life is nicer for sure. It is a free country and that shows. You don't need to be well off to enjoy life. Family time is given importance and laws ensure companies can't force you to work longer without compensation. People are nicer as well irrespective of status and race. They do their own thing and process if followed. In India, if you're driving a Mercedes, and a guy on a bike or in a "lesser" car runs into you, crowds will gather and automatically just blame you. There is this inherent jealousy and want to put down others who have it better. Only way to overcome it is with outright evidence or influence. The former still means struggle and the latter means totally chill. None of that here. Things are changing back home but still quite a way to go. [Corruption is definitely present here as well. Anyone who says you can't bribe is wrong, it is just much more expensive.]
Long term, my wife and I will leave Sydney. Ideally to go and live in Chennai or at least in the Middle-East where frequent travel to Chennai is possible. I want to be able to spend as much time with family as possible. One thing is for sure, death does not give warnings. I have seen it happen more than I would like. Family members were totally fine in the morning and were gone before sunset. I don't want to be going to spend time during their last moments. I want to be there for the good times. That's where the memories are. Once that's gone, the "what if" thought should not be there because if it is, it will be there till my time comes.
If I could, I would leave and go back today but career choices means I would not be able to lead the quality of life I want and that is the only thing stopping me.